10 years, 8 months ago.

As Yoshi said, PIC has a ton of microcontrollers, so you cannot just say the LPC1768 is better because...

Then what for sure is important is the project. Which tasks does the microcontroller have to perform?

Finally, are we talking about a company or a student project? The problem is that with your description I can see two reasons for his question: First is in a company they might do everything on PICs. Then if there is a problem and your collegue doesn't work there anymore, there is a larger chance someone else can fix it for example. Option two is that it is a PIC fanboy, because he always used PIC everyone should. Why is this an option? Because besides option 1 I don't see a reason why you would specifically demand a PIC. It could be that the LPC1768 is way overkill. But then he should have asked for a reason to use a core M3 instead of an 8-bit microcontroller.

10 years, 8 months ago.

The answer is extremely complex and partially depends on the exact PIC device or family in question, but I can speak at a high level about Cortex M vs. PIC. The ARM architecture is superior to PIC in many ways. From a core architecture point of view the load store architecture with 16, 32 bit registers provides an ideal target for 'C' compilers allowing for optimal code generation with reduced code size and higher performance than a PIC. Additional the strict Harvard architecture of a PIC creates a constrained system with limited (if any depending on the family) ability to execute code from RAM, and clumsy mechanisms to access data from flash. In contrast the ARM architecture with it's linear 4GB address space and internal bus switches allows seamless use of flash and SRAM for either code execution or data. Additionally all peripheral resisters are also mapped into this address space so they are accessible to high level languages as simple pointers in 'C' allowing for simplified code development. The interrupt system in the ARM architecture is optimized for low latency interrupt response and efficient implementation of nested interrupts from multiple sources. In addition fully programmable interrupt level (16 interrupt priorities on a LPC1768), by interrupt source allows a developer to optimize the system architecture. Contrast this to the rather limited interrupt capabilities of most PIC devices where the developer has to use great care to work within the inflexible interrupt priority system to attain adequate interrupt latency. The debug capabilities of a LPC1768 are far beyond what is available on PIC. Along with basic breakpoints the LPC1768 also provides data breakpoints and in conjunction with the Data Watchpoint and trace unit can implement unobtrusive data watchpoints and through the DAP (with the proper debugger and development tools) allow access to all internal memory while the processor is running. Lastly the LPC1768 implements the Embedded Trace Macrocell which provices unobtrusive, full speed instruction trace for efficient debug of complex problems. The benefits of a ARM based device can be best articulated when more details are know such as particulars of the application and the exact PIC device in question so these are generalities so if you can provide more detail I can be more specific as this is just the high level benefits.

10 years, 8 months ago.

The project in question is a single axis solar tracker, employing a stepper motor, two LDRs for tracking the sun, and a two AA battery charger through the panel. The battery charge status will be displayed on the LCD through the microcontroller.

Any help to put the argument in my favor will be greatly appreciated!